JP2765593B2 - Hydraulic Shovel Front Structure - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a front structure of a hydraulic shovel having a boom, an arm, and a bucket.

[Conventional technology]

FIG. 4 is a side view showing a front structure of a conventional hydraulic shovel. This conventional front structure has a driver's cab and has a main body 1 forming a revolving body, a boom 2 rotatably provided on the main body 1, and a rotation of the boom 2 via a first connecting pin 3. An arm 4 movably connected, a bucket 6 connected to the arm 4 via a second connecting pin 5, a boom cylinder 7 for rotating the boom 2, and an arm for rotating the arm 4. Cylinder 8 and bucket 6
And a bucket cylinder 9 for rotating the cylinder.

The bucket 6 is equipped with a tilt angle sensor 10 for slope excavation work and leveling work. The main body 1 has a logical judgment function as illustrated in FIG.
And a control valve 12 that drives according to the signal output from the controller 11 and controls the driving of the arm cylinder 8 and the boom cylinder 7. ing.

In the case of a hydraulic shovel, slope excavation as illustrated in FIG. 4 is often performed in which excavation is performed along a sloping ground or the like while keeping a bucket rotation angle constant. Conventionally, at the time of this slope excavation, a reference angle is set in advance in the controller 11, the angle output from the inclination angle sensor 10 is compared with the reference angle in the controller 11, and when they match, the control valve 12 is neutralized, for example, The arm cylinder 8 is held in the extended state at that time. When the angle output from the tilt angle sensor 10 changes with the operation of the boom 2 and the arm 4, the output angle is compared with the reference angle by the controller 11 at any time,
If they do not match, a signal corresponding to the deviation angle is output to the control valve 12 and this control valve 12
, The arm cylinder 8 is actuated accordingly, and the control valve 12 is neutralized when the deviation angle becomes zero, which is repeated.

[Problems to be solved by the invention]

By the way, as described above, in the conventional technique of performing a slope excavation or the like using the inclination angle sensor 10, the controller 11
The signal value of the tilt angle sensor 10 compared with the reference angle inevitably has a time delay with respect to the actual tilt state,
First, it is necessary to control the drive of the control valve 12 based on the signal value of the time delay. Second, the pressure oil supplied to the arm cylinder 8 or the like via the control valve 12 is itself. Due to the compressibility, there is also a time delay between the operation of the control valve 12 and the operation of the arm cylinder 8 during the supply of the pressure oil. Shift occurs during the operation for following the cylinder 8 and the like,
As a result, it is difficult to maintain the inclination angle in real time, and there is a problem that it is difficult to realize highly accurate slope excavation.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances in the related art, and has as its object to provide a front structure of a hydraulic shovel capable of performing work by constant bucket rotation angle control without providing an inclination angle sensor. It is in.

[Means for solving the problem]

In order to achieve this object, the present invention provides a boom rotatably provided on a main body, an arm rotatably connected to the boom via a first connection pin, and a second boom mounted on the arm. In a front structure of a hydraulic shovel including a bucket connected via a connection pin, one end is rotatably connected to the bucket via a third connection pin, and the first connection pin and the second connection are connected to each other. The structure is such that an arm link is provided in parallel with the direction connecting the pins.

[Action]

According to the present invention, since the arm link is provided as described above, the first connecting pin, the second connecting pin, the third connecting pin, and the arm link form a parallelogram, and accordingly, the arm is provided. The bucket turning angle can be kept constant without being affected by the turning motion of the bucket. That is, it is possible to carry out the work by the constant control of the bucket rotation angle without providing the tilt angle sensor. Therefore, the work is affected by the time delay of the signal output from the tilt angle sensor and the time delay due to the compressibility of the oil. The desired operation can be performed mechanically with a constant bucket rotation angle by the parallelogram link.

〔Example〕

Hereinafter, an embodiment of a front structure of a hydraulic shovel of the present invention will be described with reference to the drawings.

FIG. 1 is a side view showing a first embodiment of the present invention, FIG. 2 is a side view showing a second embodiment of the present invention, and FIG. 3 is a side view showing a third embodiment of the present invention. It is.

In FIGS. 1 to 3, the same components as those described above are denoted by the same reference numerals. That is, these first to first
Also in the first to third embodiments shown in FIG. 3, a boom 2 connected to a main body 1 and an arm 4 connected to the boom 2 via a first connecting pin 3 are used as front structural members of the hydraulic shovel. In addition to a bucket 6 connected to the arm 4 via a second connecting pin 5, a boom cylinder 7 for rotating the boom 2 and an arm cylinder 8 for rotating the arm 4 are provided. The above-described bucket cylinder 9 shown in FIG. 4 is not provided in each of these embodiments.

In the first embodiment shown in FIG. 1, the distal end of the boom 2 is set to have a large width. One end is connected to the bucket 6 via a third connecting pin 20 so as to be freely rotatable.
The arm link 21 is provided in parallel with the direction connecting the connecting pin 3 and the second connecting pin 5. The other end of the arm link 21 is connected to the boom 2 via the fourth connecting pin 22. It is rotatably connected. The length between the first connecting pin 3 and the fourth connecting pin 22 is set substantially equal to the length between the second connecting pin 5 and the third connecting pin 20. Yes, 4 connecting pins 3,5,2 including link 21 for arm
A parallelogram link is formed by 0,21.

In the first embodiment configured as described above, the arm link 21 is connected to the third connection pin 20 and the fourth connection pin as described above.
Since the parallelogram link is formed by connecting the bucket 6 and the boom 2 via 22, the direction connecting the second connecting pin 5 and the third connecting pin 20 by holding the boom 2 stationary Is determined, that is, the rotation angle of the bucket 6 with respect to the ground contact surface is determined to be α. Here, when the arm cylinder 8 is driven to rotate the arm 4, the bucket 6 is moved by the rotation of the arm 4, for example, to the first position.
Although it moves upward as shown by the broken line in the figure, the direction connecting the second connecting pin 5 and the third connecting pin 20 is parallel to the direction connecting the first connecting pin 3 and the fourth connecting pin 22. Thus, the rotation angle of the bucket 6 is kept constant at α.

Therefore, it is possible to mechanically perform a work such as a slope excavation for keeping the rotation angle of the bucket 6 constant without being affected by the operation of the arm 4, that is, without requiring any inclination angle sensor. In addition, since there is no time delay or the like associated with the inclination angle sensor, highly accurate work can be realized. Further, in the first embodiment, the arm link 2 does not need the bucket cylinder, the link and the pin for transmitting the movement of the bucket cylinder to the bucket 6, and the tilt angle sensor.
1, since the third connection pin 20 and the fourth connection pin 22 are provided in a simple configuration, the number of constituent members is small and the manufacturing cost can be reduced.

The second embodiment shown in FIG. 2 is provided with an auxiliary link 23 arranged in parallel to the direction connecting the second connecting pin 5 and the third connecting pin 20 and connecting the other end of the arm cylinder 21 to the fourth. And a cylinder 24 capable of changing the position of the fourth connecting pin 22 while being rotatably connected to the auxiliary link 23 via the connecting pin 22. The upper end of the auxiliary link 23 is connected to the first connection pin 3, and the cylinder 24 is connected to the boom 2 so as to be freely rotatable.

In the second embodiment configured as described above, the arm 4
A high-precision work can be performed by keeping the rotation angle of the bucket 6 constant, irrespective of the operation described above, and the position of the fourth connection pin 22 can be adjusted by the expansion and contraction operation of the cylinder 24 without rotating the boom 2. That is, the rotation angle of the bucket 6 can be easily changed.

In the third embodiment shown in FIG. 3, a first auxiliary link 23 is provided in parallel with the direction connecting the second connecting pin 5 and the third connecting pin 20. The other end of the arm link 21 is provided. Are connected to a first auxiliary link 23 via a fourth connecting pin 22 so as to be rotatable, and a fifth connecting pin 25 for rotatably connecting the boom 2 to the main body 1 and a first connecting pin 3 And a boom link 26 having one end connected to the fourth connecting pin 22 and a boom link 26 having one end connected to the direction connecting the first connecting pin 3 and the fourth connecting pin 22. Is connected to the fifth connecting pin 25, and the other end is connected to the other end of the boom link 26 by the sixth connecting pin 27.
And a cylinder 29 capable of changing the position of the sixth connecting pin 27.
The cylinder 29 is rotatably connected to the main body 1.

In the third embodiment configured as described above, the first connecting pin 3, the fourth connecting pin 22, the sixth connecting pin 27,
Since the parallelogram link is also formed by the connecting pin 25 and the boom link 26, the cylinder 29 is held stationary and the position of the sixth connecting pin 27 is fixed, so that the second connecting pin 5 And the direction connecting the third connection pin 20 is parallel to the direction connecting the fifth connection pin 25 and the sixth connection pin 27,
Irrespective of the operation of the boom 2 and the arm 4, high-precision work can be performed while keeping the rotation angle of the bucket 6 constant, and the position of the sixth connecting pin 27, The rotation angle of the bucket 6 can be easily changed.

〔The invention's effect〕

Since the present invention has a configuration in which a parallelogram link is formed by providing an arm link as described above, it is possible to perform work by bucket bucket angle constant control without providing an inclination angle sensor. Since there is no fear of causing a time delay of a signal or a time delay due to oil compressibility during the operation, there is an effect that a highly accurate operation can be realized.

[Brief description of the drawings]

FIG. 1 is a side view showing a first embodiment of a front structure of a hydraulic shovel of the present invention, FIG. 2 is a side view showing a second embodiment of the present invention, and FIG. 3 is a third embodiment of the present invention. FIG. 4 is a side view showing a front structure of a conventional hydraulic shovel, and FIG. 5 is a view showing a relationship between an inclination angle sensor, an arm cylinder, and a boom cylinder provided in the hydraulic shovel shown in FIG. It is a block diagram shown. 1 ... body, 2 ... boom, 3 ... first connecting pin, 4
... arm, 5 ... second connection pin, 6 ... bucket,
20 ... third connecting pin, 21 ... arm link, 22 ...
4th connecting pin, 23 ... auxiliary link, 24 ... cylinder,
25 Fifth connecting pin, 26 Boom link, 27
Sixth connecting pin, 28 ... second auxiliary link, 29 ... cylinder.

Claims (4)

(57) [Claims] 1. A boom rotatably provided on a main body, an arm rotatably connected to the boom via a first connecting pin, and an arm connected to the arm via a second connecting pin. In the front structure of the hydraulic shovel including a bucket, one end is rotatably connected to the bucket via a third connection pin, and is parallel to a direction connecting the first connection pin and the second connection pin. The front structure of the hydraulic shovel, wherein an arm link is provided. 2. The other end of the arm link is rotatably connected to the boom via a fourth connecting pin, and the length between the first connecting pin and the fourth connecting pin, and the second The front structure of a hydraulic shovel according to claim 1, wherein a length dimension between the connecting pin and the third connecting pin is set to be substantially equal. 3. An auxiliary link arranged in parallel to a direction connecting the second connecting pin and the third connecting pin, and the other end of the arm link is pivoted to the auxiliary link via the fourth connecting pin. The front structure of a hydraulic shovel according to claim 1, further comprising a cylinder that can be freely connected and that can change the position of the fourth connection pin. 4. A first auxiliary link arranged in parallel to a direction connecting the second connecting pin and the third connecting pin, and the other end of the arm link is connected to the auxiliary link via the fourth connecting pin. For a boom that is rotatably connected and that is arranged parallel to the direction connecting the fifth connection pin and the first connection pin that rotatably connects the boom to the main body, and has one end connected to the fourth connection pin. A link is arranged parallel to the direction connecting the first connection pin and the fourth connection pin, one end is connected to the fifth connection pin, and the other end is connected to the other end of the boom link by a sixth connection pin. 2. The front structure of a hydraulic shovel according to claim 1, further comprising: a second auxiliary link connected through a second connecting pin; and a cylinder capable of changing a position of the sixth connecting pin.